Recently I and a friend from another university were out drinking together in her college's town. We became heavily intoxicated and took a cab back to her dorms for the night rather than risk the long walk back. After having been asleep in her unused second bed, sometime during the night I left her dormitory room to use the restroom, and unknowingly walked into the wrong room next door.
I was awoken shortly after by a number of police officers - apparently the owner of the unlocked dorm room into which I had unwittingly walked returned several hours later and called the police upon finding a stranger in the bed. The officers proceeded to lead me (still quite intoxicated after only a few brief hours of sleep) out of the dorms and interrogate me outside shortly before arresting me for public drunkenness and transporting me to the police station, where they detained me until I was fully sober and presented me with a citation and told me to contact the magistrate listed regarding a trial.
This is the first time I have ever been charged with a criminal offense or misdemeanor, and I am wondering how to proceed. Obviously I consider the charge ridiculous, given that the extent of my wrongdoing was while under the influence (not to mention exhausted) to walk into a wrong door in a dark hallway, but of course a judge might not see it the same way, and there's no denying that I was quite drunk at the time of my mistake - though I was never aware a private dormitory was a "public" space.
Assuming it's a lost cause to enter a not guilty plea, is my best bet in seeking one of these community service "diversion programs" I've heard of for first-time offenders in order to keep a conviction from getting on my permanent record? Do I need to plead guilty in order to seek that option, and if so I am at risk for the judge not allowing that possibility? How necessary (if it all) is it for me to hire a lawyer, and if so how do I go about doing that (being incredibly poor and lacking any personal connections to one)? The most vital issue for me is keeping my permanent record clean of conviction, if at all possible.
Thanks in advance for your time and advice.

